I don't know...whenever I feel like it. I'm still in search of my "god phone".
If the LG V10 had this years specs it would be the one.
For now I've decided to leave the premium phone market and go after mid range phones (I was buying like 4 new phones a year). Even with Ebay that's an expensive habit. My new phone is the LG Stylo and it's working just fine, but the camera needs some love.
Well I have 15 phones on my google account listed. I sometimes change 3 times in a year, sometimes I will go longer than a year. I never go longer than that though.
I switch my smartphone average at 12, 18 months... but not because I like to buy phones... they become too slow for working with them... :'( Even if I think that now with the P8 I'll have less problems.